extern: Update cgltf to 1.15

This incorporates all custom patches our version had and syncs to the
officially released version again.

Author: zeux

extern/cgltf.h

@@ -1,7 +1,7 @@
 /**
  * cgltf - a single-file glTF 2.0 parser written in C99.
  *
- * Version: 1.14
+ * Version: 1.15
  *
  * Website: https://github.com/jkuhlmann/cgltf
  *
@@ -376,13 +376,29 @@ typedef struct cgltf_image
 	cgltf_extension* extensions;
 } cgltf_image;
 
+typedef enum cgltf_filter_type {
+    cgltf_filter_type_undefined = 0,
+    cgltf_filter_type_nearest = 9728,
+    cgltf_filter_type_linear = 9729,
+    cgltf_filter_type_nearest_mipmap_nearest = 9984,
+    cgltf_filter_type_linear_mipmap_nearest = 9985,
+    cgltf_filter_type_nearest_mipmap_linear = 9986,
+    cgltf_filter_type_linear_mipmap_linear = 9987
+} cgltf_filter_type;
+
+typedef enum cgltf_wrap_mode {
+    cgltf_wrap_mode_clamp_to_edge = 33071,
+    cgltf_wrap_mode_mirrored_repeat = 33648,
+    cgltf_wrap_mode_repeat = 10497
+} cgltf_wrap_mode;
+
 typedef struct cgltf_sampler
 {
 	char* name;
-	cgltf_int mag_filter;
-	cgltf_int min_filter;
-	cgltf_int wrap_s;
-	cgltf_int wrap_t;
+	cgltf_filter_type mag_filter;
+	cgltf_filter_type min_filter;
+	cgltf_wrap_mode wrap_s;
+	cgltf_wrap_mode wrap_t;
 	cgltf_extras extras;
 	cgltf_size extensions_count;
 	cgltf_extension* extensions;
@@ -854,6 +870,8 @@ void cgltf_node_transform_world(const cgltf_node* node, cgltf_float* out_matrix)
 
 const uint8_t* cgltf_buffer_view_data(const cgltf_buffer_view* view);
 
+const cgltf_accessor* cgltf_find_accessor(const cgltf_primitive* prim, cgltf_attribute_type type, cgltf_int index);
+
 cgltf_bool cgltf_accessor_read_float(const cgltf_accessor* accessor, cgltf_size index, cgltf_float* out, cgltf_size element_size);
 cgltf_bool cgltf_accessor_read_uint(const cgltf_accessor* accessor, cgltf_size index, cgltf_uint* out, cgltf_size element_size);
 cgltf_size cgltf_accessor_read_index(const cgltf_accessor* accessor, cgltf_size index);
@@ -2322,6 +2340,18 @@ const uint8_t* cgltf_buffer_view_data(const cgltf_buffer_view* view)
 	return result;
 }
 
+const cgltf_accessor* cgltf_find_accessor(const cgltf_primitive* prim, cgltf_attribute_type type, cgltf_int index)
+{
+	for (cgltf_size i = 0; i < prim->attributes_count; ++i)
+	{
+		const cgltf_attribute* attr = &prim->attributes[i];
+		if (attr->type == type && attr->index == index)
+			return attr->data;
+	}
+
+	return NULL;
+}
+
 cgltf_bool cgltf_accessor_read_float(const cgltf_accessor* accessor, cgltf_size index, cgltf_float* out, cgltf_size element_size)
 {
 	if (accessor->is_sparse)
@@ -4296,6 +4326,7 @@ static int cgltf_parse_json_diffuse_transmission(cgltf_options* options, jsmntok
 
 	// Defaults
 	cgltf_fill_float_array(out_diff_transmission->diffuse_transmission_color_factor, 3, 1.0f);
+	out_diff_transmission->diffuse_transmission_factor = 0.f;
 
 	for (int j = 0; j < size; ++j)
 	{
@@ -4461,8 +4492,8 @@ static int cgltf_parse_json_sampler(cgltf_options* options, jsmntok_t const* tok
 	(void)options;
 	CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_OBJECT);
 
-	out_sampler->wrap_s = 10497;
-	out_sampler->wrap_t = 10497;
+	out_sampler->wrap_s = cgltf_wrap_mode_repeat;
+	out_sampler->wrap_t = cgltf_wrap_mode_repeat;
 
 	int size = tokens[i].size;
 	++i;
@@ -4479,28 +4510,28 @@ static int cgltf_parse_json_sampler(cgltf_options* options, jsmntok_t const* tok
 		{
 			++i;
 			out_sampler->mag_filter
-				= cgltf_json_to_int(tokens + i, json_chunk);
+				= (cgltf_filter_type)cgltf_json_to_int(tokens + i, json_chunk);
 			++i;
 		}
 		else if (cgltf_json_strcmp(tokens + i, json_chunk, "minFilter") == 0)
 		{
 			++i;
 			out_sampler->min_filter
-				= cgltf_json_to_int(tokens + i, json_chunk);
+				= (cgltf_filter_type)cgltf_json_to_int(tokens + i, json_chunk);
 			++i;
 		}
 		else if (cgltf_json_strcmp(tokens + i, json_chunk, "wrapS") == 0)
 		{
 			++i;
 			out_sampler->wrap_s
-				= cgltf_json_to_int(tokens + i, json_chunk);
+				= (cgltf_wrap_mode)cgltf_json_to_int(tokens + i, json_chunk);
 			++i;
 		}
 		else if (cgltf_json_strcmp(tokens + i, json_chunk, "wrapT") == 0)
 		{
 			++i;
 			out_sampler->wrap_t
-				= cgltf_json_to_int(tokens + i, json_chunk);
+				= (cgltf_wrap_mode)cgltf_json_to_int(tokens + i, json_chunk);
 			++i;
 		}
 		else if (cgltf_json_strcmp(tokens + i, json_chunk, "extras") == 0)